Antifungal Effect of Bacillus velezensis ZN-S10 against Plant Pathogen Colletotrichum changpingense and Its Inhibition Mechanism

Abstract

In order to optimize crop production and mitigate the adverse impacts associated with the utilization of chemical agents, it is necessary to explore new biocontrol agents. Bacillus velezensis has been widely studied as a biocontrol agent because of its efficient and ecofriendly plant disease control mechanisms. This study shows that the strain ZN-S10 effectively reduces the area of leaf spots caused by the pathogen Colletotrichum changpingense ZAFU0163-1, which affects conidia production and germination, inhibits mycelium growth, and induces mycelium deformation. In antifungal experiments with crude extracts, we observed a delay in the cell cycle of conidia, which may be responsible for the inhibition of conidial germination. Among the bioactive metabolites detected through integrated LC-MS- and GC-MS-based untargeted metabolomics, 7-O-Succinyl macrolactin A, telocinobufagin, and surfactin A may be the main antifungal metabolites of strain ZN-S10. The presence of 7-O-Succinyl macrolactin A could explain the cell damage in germ tubes. This is the first report of telocinobufagin detected in B. velezensis. These results are significant for understanding the inhibitory mechanisms employed by B. velezensis and should serve as a reference in the production of biocontrol agents.

Bacillus megaterium: Evaluation of Chemical Nature of Metabolites and Their Antioxidant and Agronomics Properties

“…A total of 75 compounds were found to be present in BC extracts and not present in CS2 extracts, as illustrated in Table 3 for analysis without derivatization, and in Table 4 for analysis with derivatization. Some of these identified compounds were strictly found in BC extracts, suggesting a probable production by B. megaterium: 10 fatty acids derivatives (23 ′ , 32 ′ , 34 ′ , 39 ′ , 42 ′ , 44 ′ , 46 ′ , 47 ′ , 36, 44), 5 linear hydrocarbons (4,12,20,24,25), 5 cyclic hydrocarbons with 3 isomers (5,6,8,9,10,11,15,18), 6 amino acids (10 ′ , 12 ′ , 15 ′ , 18 ′ , 20 ′ , 22 ′ ), 2 dipeptides (29, 47), 2 cyclic dipeptides (46, 64), 6 aromatic hydrocarbons (1,16,26,27,31,33), 2 phthalates (59, 61), 2 sugar acids with 1 isomer (9 ′ , 24 ′ , 41 ′ ), 4 polyols with 1 isomer (2 ′ , 4 ′ , 5 ′ , 6 ′ , 21 ′ ), 2 cyclitols (29 ′ , 43 ′ ) and 17 others were identified (3,7,13,14,19,21,23,32,37,43,45,48,50,62, 63, 17 ′ , 38 ′ ). tr indicates integration inferior to 0.1 × 10 6 ; "ND": not detected.…”

“…Improving the production and quality of food is currently problematic, remaining too dependent on antibiotics, synthetic fertilizers or pesticides [1]. The intensive use of these compounds has led to the emergence of pathogen resistance and severe negative environmental impacts and has thus become an important issue of public health and environment pollution [2][3][4]. New biological alternatives are urgently needed to counter and reverse the spread of these issues.…”